If that wasn't upsetting enough, the letter also tells her that she has a retarded kid and "should deal with it properly".

"What right do you have to do this to hard working people!!!!!!!! I HATE people like you who believe, just because you have a special needs kid, you are entitled to special treatment!!! GOD!!!!!!"

The writer finishes by demanding the family "go live in a trailer in the woods or something with your wild animal kid!!!" and asks the family to do the right thing and move or "euthanize him. Either way, we are ALL better off!!!"

The letter which was anonymously posted has shocked the family. Picture: GawkerSource:Supplied

The family are searching for the letter writer. Picture: GawkerSource:Supplied

Max stays with his grandmother Brenda Millson in the mornings during summer, but the letter was delivered to her Newcastle home.

The angry grandmother said she was shaking when she read the awful letter.

But the letter soon went viral and the neighbourhood has now joined forces behind the Begley family to find the anonymous culprit.

The family say they are so upset and angry they are considering pressing charges against the person who wrote the letter.